What test to use?

#1
Hey guys.

first of all it is a theoretical project, so no animals or something were hurt.

So we have 6 rats. At the beginning we measure the pain-threshold as a baseline.
After that the rats receive a chronic injury and a electrode in implanted in a certain brain area.

Now we have three consecutive days of measurement. Each day there is a pre-test for pain threshold, then stimulation and then the post test.

1528799367020.png

the data set looks like this.
In the analysis the baseline can be ignored (will just be used as a visual representation in a graph).
I'm not interested in the changes of pain-threshold over time. Just: is there a difference in pain threshold caused by stimulation (difference from pre to post test).
I never worked with more than one pre- post test, so i'm kinda stuck


Thank you guys,